Plumb Line Research Articles

Outcomes of Surgical Treatment for One Hundred and Thirty-Eight Patients With Severe Sagittal Deformity at a Minimum 2-Year Follow-Up

Abstract INTRODUCTION Operative treatment of ASD can be very challenging with high complication rates. It's well established that pts benefit from such treatment. However, the surgical outcomes for pts with severe sagittal deformity have not been reported. METHODS Retrospective review of a prospective, multicenter adult spinal deformity (ASD) database. Inclusion criteria: operative patients age = 18, SVA = 15 cm, PI-LL = 30 degrees, and/or lumbar kyphosis = 5 degrees with a minimum 2 yr follow-up. Health-related quality of life (HRQOL) scores: Oswestry Disability Index (ODI), Short form-36 (SF36), Scoliosis Research Society (SRS22), back/leg pain numerical rating scale (NRS) and min clinically important difference (MCID)/substantial clinical benefit (SCB) for patients eligible to meet it. Radiographic values: max coronal cobb angle, coronal C7 plumb line, pelvic tilt, mismatch between pelvic incidence and lumbar lordosis, thoracic kyphosis, C7 sagittal vertical axis. Demographic, frailty, surgical, and complication data were also collected. Comparisons between 2 yr postop and baseline HRQOL/radiographic data were made. P < .05 was significant. RESULTS About 138 patients were included from 502 operative patients (54.3% females, average age 63.3 ± 11.5 yr). Averege baseline frailty score was 4.1 ± 1.4, indicating that patients were frail. A total of 71 (51.4%) of the patients had a prior fusion. A total of 89.9% patients had posterior fusion only, with an average 11.5 ± 4.1 post levels fused. About 44.9% had 3-column osteotomy. Two standard deviations was considered for for SVA = 14.8 cm. All 2-yr postop radiographic parameters were significantly improved compared to baseline (P < .05) except coronal C7 plumb line (P > .05). All 2-yr HRQOL measures were significantly improved compared to baseline (P < .004). About 46.6% to 73.8% of patients met either MCID or SCB for all HRQOL. A total of 74.6% of patients had at least 1 complication, 11.6% had 4 or more complications, 33.3% had a minimum 1 major complication, and 42 (30.4%) had a postop revision. CONCLUSION Patients with a severe sagittal malalignment benefit from surgical correction at 2 yr postop both radiographically and clinically despite having a high complication rate.

Coronal and sagittal spinal alignment in lumbar disc herniation with scoliosis and trunk shift

BackgroundTo investigate the incidence of scoliosis and trunk shift in patients with LDH (lumbar disc herniation) and analyze the differences in spinopelvic alignment among patients with or without trunk shift and non-symptom controls.Materials and methodsAll included subjects had standard upright antero-posterior and lateral radiographs of the whole spine taken. Evidence of disc herniation was confirmed by computed tomography or magnetic resonance imaging. The parameters measured included trunk shift and Cobb angle, TK (thoracic kyphosis), TLK (thoraco-lumbar junction kyphosis), LL (lumbar lordosis), PI (pelvic incidence), SS (sacral slope), PT (pelvic tilt) and SVA (sagittal vertical axis).ResultsSixty-eight patients with LDH and 61 controls were included. There were significantly more male patients with trunk shift than the patients without trunk shift. Forty-two patients had curve magnitudes ranging from 5 to 38°. The trunk shift ranged from 0.5 to 7.3 cm. A total of 54.76% of patients had a disc herniation on the concave side of the main curve. Fifty percent of patients showed a trunk shift towards the opposite side of disc herniation. There were significant differences in spinopelvic parameters among groups. Significant correlations were also observed between several spinopelvic parameters in the three groups. However, the degrees of correlations among the spinopelvic parameters differed among the three groups.ConclusionSpinal sagittal morphology in LDH patients with trunk shift exhibits a more anterior shift of the C7 plumb line, less LL, and a more horizontal sacrum. Correlation analysis indicated a disharmonious spinopelvic interaction and a change in the compensatory model in patients with LDH.

Ergonomic assessment of robotic general surgeons: a pilot study.

Inadequacies exist in the ergonomics of upper body positioning of robotic surgeons; these deficits in biomechanical efficacy predispose surgeons to musculoskeletal injury. Ergonomics and biomechanics may be objectively measured using the Rapid Entire Body Assessment (REBA) and the Rapid Upper Limb Assessment (RULA) to quantify ergonomic efficacy. The purpose of this study is to use validated ergonomic tools to assess the posture of robotic surgeons to examine deficiencies. Four robotic surgeons using the da Vinci model were observed for a minimum of 30min each. An Xbox connect camera was positioned 10feet away from the surgeon console. Kinetisense software measured position of the head, shoulders, mid-spine, hips, and knees. One image was captured every 30s. The software measured the positions in centimeters that deviated from an ideal central postural line (plumb line). RULA and REBA were also employed to assess posture using a still image at 15min. The average RULA score for the four surgeons was 4.75 (range 3-6). The average REBA score for the four surgeons was 7 (range 5-8). The average RULA score of 4.5/7 and the average REBA of 7/15 qualify as medium risk with the recommendation that action is needed to improve ergonomics. While this pilot study is limited in size, it demonstrates the need for further investigation. With more than half of surgeons reporting musculoskeletal pain after robotic surgery (McDonald et al. in Gynecol Oncol 134:243-247, 2014), poor posture may offer an explanation.

Calibration and Measurement Study on Density of Selective Laser Sintered 3D Printing Powder Bed

The commonly used method for measuring the density of a selective laser sintered powder bed is to extract a certain volume of powder bed powder, measure the mass of the powder, and then calculate the density of the powder bed using the mass formula. Aiming at the shortcomings of the existing methods, such as complex operation and low measurement accuracy, this paper proposes a method based on plumb bob method for selective laser sintering powder bed density measurement. The method can measure the density of the powder bed without causing large damage to the powder bed, and the measurement efficiency and precision are higher than the existing measurement methods. In this test, the most commonly used ABS powder was used, and its density was calibrated using the plumb method. The function of the depth between the depth of the plumb bobbin and the density of the powder bed was fitted to the density of the powder bed. The measurements provide data support.

Spinal Balance/Alignment - Clinical Relevance and Biomechanics.

In the normal spine due to its curvature in various regions, C7 plumb line (C7PL) passes through the sacrum so that the head is centered over the pelvis-ball and socket hip joints and ankle joints. This configuration leads to the least muscular activities to maintain the spinal balance. For any reason like deformity, scoliosis, kyphosis, trauma, and/or surgery this optimal configuration gets disturbed requiring higher muscular activity to maintain the posture and balance. Several parameters like the thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), Hip- and leg position influence the sagittal balance and thus the optimal configuration of spinal alignment. Global sagittal imbalance is energy consuming and often painful compensatory mechanisms are developed, that in turn negatively influence the quality of life. This review looks at the clinical aspects of spinal imbalance, and the biomechanics of spinal balance as dictated by the deformities- ankylosing spondylitis, scoliosis and kyphosis; surgical corrections- pedicle subtraction osteotomies and long segment stabilizations and consequent postural complications like the proximal and distal junctional kyphosis. This review suggests several potential research topics as well.

Sedentary Behavior and Physical Inactivity among College Students Affect Core Strength, Flexibility, and Posture

Sedentary behavior and physical inactivity have increased with advancements in technology. College students are high utilizers of computers and mobile devices, often for long periods with poor posture, putting them at risk for negative health consequences. PURPOSE: To evaluate the effects of sedentary behavior and physical activity participation on core strength, flexibility, and posture in college students. METHODS: College students (N=33; n=22 female, n=11 male) completed physical measures and questionnaires of sedentary behavior (SB) and physical activity (PA). Curl-up tests, sit and reach, and plumb line assessments indicated core strength, flexibility, and posture, respectively. Two-way ANOVAs were performed with participants categorized by their posture measures (rounded shoulders; RS, and forward head posture; FHP) on weekday and weekend SB, and PA per week. Associations were determined between SB, PA, core strength, flexibility, and body fat percentage by computing Pearson’s correlation coefficients. RESULTS: There were no significant differences in SB and PA between postural groups. However, participants with RS and FHP spent an hour more per day being sedentary on average than those with RS alone (RS & FHP: SB weekday, M=3.74 hrs ± 0.79, SB weekend, M= 3.74 hrs ± 0.9; RS only: SB weekday, M= 2.62 hrs ± 0.36, SB weekend, M= 2.77 hrs ± 0.48). SB was associated with decreased flexibility (SB weekday: r=-0.47, p<0.01; SB weekend: r=-0.48, p<0.01), while physical inactivity was associated with higher body fat percentage (r=0.36, p=0.04) and decreased core strength (r=-0.51, p<0.01). Furthermore, college students who were sedentary during the week were also sedentary on the weekend (r=0.82, p<0.01). CONCLUSIONS: Sedentary behavior and physical inactivity were associated with negative changes in core strength, flexibility, posture, and body composition. Interventions targeting improvements in these behaviors among college students should include guidance on reducing screen time and limiting improper posture.

Factors Predicting the Surgical Risk of Osteoporotic Vertebral Compression Fractures.

The aim of our study was to investigate the association between global spinal alignment, spinopelvic parameters, and outcomes of osteoporotic vertebral compression fractures (OVCF). Patients with vertebral compression fractures seen at our hospital between October 2017 and November of 2018 with a bone mineral density (BMD) T-score < −2.5 were recruited for the study. Surgical intervention was performed after eight weeks of conservative treatment depending on clinical symptoms and the willingness of patients. Spinopelvic and sagittal alignment parameters were compared between patients who had surgery and those that did not. Seventy-nine patients were included in the study. Twenty-five patients (31.6%, mean age: 73.28 ± 9.78 years) received surgery, and 54 (68.3%, mean age: 73 ± 8.58 years) conservative treatment only. Pelvic tilt, pelvic incidence, and local kyphotic angle were statistically different between the groups (all p < 0.05). A sagittal vertical axis ≥ 50 mm, distance between the C7 plumb line and the center of the fractured vertebra (DSVA) ≥ 60 mm, pelvic incidence outside of the range of 44 to 62°), and pelvic tilt ≥ 27° were associted with the need for surgical intervention. Measurement of spinopelvic parameters can predict the need for surgery in patients with OVCF.

Incidence and Risk Factors of Cervical Kyphosis in Patients with Adolescent Idiopathic Scoliosis

Cervical kyphosis (CK) has been reported in patients with adolescent idiopathic scoliosis (AIS). The report about the incidence of CK between patients with AIS and normal populations was little. Patients included in previous studies often required scoliosis surgery (Cobb angle ≥40°), which does not represent all patients with AIS. The aims of this study were to compare incidence of CK between patients with AIS (Cobb angle >10°) and an age-matched normal population and to identify risk factors related to CK, especially coronal parameters that have rarely been studied in current literature. Patients with AIS (n= 112) and asymptomatic subjects from the general population (control group; n= 40) were retrospectively analyzed. Radiographic parameters of coronal and sagittal plane were measured on full-length spine x-rays. Patients with AIS were divided into 2 groups based on cervical lordosis angle: cervical lordosis and CK. CK was observed in 14 of 40 (35%) subjects in the control group and 68 of 112 (60.7%) patients with AIS. Several parameters were related to CK, including major curve, proximal thoracic, and main thoracic Cobb angle; proximal thoracic kyphosis angle; main thoracic kyphosis angle; T1 slope; sagittal vertical axis; vertical distance between C7 plumb line and center sacral vertical line; apical vertebral translation; T1 coronal tilt; and lumbar pelvic relationship. Logistic regression identified main thoracic Cobb angle, main thoracic kyphosis angle, sagittal vertical axis, lumbar pelvic relationship, and apical vertebral translation as independent risk factors of CK. Incidence of CK increases in patients with AIS relative to normal subjects. Coronal parameters of the spine could influence cervical sagittal alignment.

How Cervical Reconstruction Surgery Affects Global Spinal Alignment.

BACKGROUNDThere have been no reports describing how cervical reconstruction surgery affects global spinal alignment (GSA).OBJECTIVETo elucidate the effects of cervical reconstruction for GSA through a retrospective multicenter study.METHODSSeventy-eight patients who underwent cervical reconstruction surgery for cervical kyphosis were divided into a Head-balanced group (n = 42) and a Trunk-balanced group (n = 36) according to the values of the C7 plumb line (PL). We also divided the patients into a cervical sagittal balanced group (CSB group, n = 18) and a cervical sagittal imbalanced group (CSI group, n = 60) based on the C2 PL-C7 PL distance. Various sagittal Cobb angles and the sagittal vertical axes were measured before and after surgery.RESULTSCervical alignment was improved to achieve occiput-trunk concordance (the distance between the center of gravity [COG] PL, which is considered the virtual gravity line of the entire body, and C7 PL < 30 mm) despite the location of COG PL and C7PL. A subsequent significant change in thoracolumbar alignment was observed in Head-balanced and CSI groups. However, no such significant change was observed in Trunk-balanced and CSB groups. We observed 1 case of transient and 1 case of residual neurological worsening.CONCLUSIONThe primary goal of cervical reconstruction surgery is to achieve occiput-trunk concordance. Once it is achieved, subsequent thoracolumbar alignment changes occur as needed to harmonize GSA. Cervical reconstruction can restore both cervical deformity and GSA. However, surgeons must consider the risks and benefits in such challenging cases.

Sequential drinking water sampling as a tool for evaluating lead in flint, Michigan

Eliminating the sources of human lead exposure is an ongoing public health goal. Identifying the make-up of household plumbing and service line material type is important for many reasons including understanding lead release sources and mechanisms, targeting locations for lead service line (LSL) removal, and assessing the effectiveness of lead remediation strategies. As part of the response to Flint, Michigan's drinking water lead public health crisis, a return to their original drinking water source (Lake Huron) and an increase in orthophosphate dose was implemented in late 2015. In 2016, EPA performed multiple rounds of sequential or “profiling” water sampling to evaluate corrosion control effectiveness and identify lead sources in homes and service lines, as well as to evaluate the effectiveness of corrosion control treatment with time on the different plumbing components. The results showed that lead levels, including high lead levels likely associated with particles, decreased with time in homes sampled during the 11-month evaluation period. Although sequential sampling indicated that brass fittings, brass fixtures, and galvanized pipes were lead sources, LSLs were the greatest source of lead when present. Following the removal of LSLs, the total mass of lead contributed to the drinking water decreased by 86% on average.

Screening and Early Identification of Spinal Deformities and Posture in 311 Children: Results from 16 Districts in Slovakia.

Objective In our study, we wanted to identify the number of existing deformities of the spine and posture in primary schoolers. Methods The sample consisted of 311 healthy pupils aged 6-7. We used Klein, Thomas, and Mayer method to evaluate the posture. The spine curvature was evaluated by plumb line. Muscle imbalance was evaluated by standardized manual tests by Professor Janda. The results were evaluated by the basic population abundance and the use of the ANOVA program. We determined the level of statistical significance at p = 0.05. Results The statistically significant occurrence of poor posture was found. Poor posture occurred in more than 50% of the pupils studied. Spine deformities in the sagittal plane have exceeded 30% (C = 37.94212%; Th = 32.15434%; L = 30.22508%). In the frontal plane deformities were present in 13.18328% of pupils. Spinae and postural disorders were accompanied by the muscle imbalance (muscle stiffness and weakness). Conclusion Screening is a well-founded technique for the early detection of spinae and posture disorders. Based on the results of screening, professionals can take preventive measures. As in our research prevalence of spine deformities and poor posture in children was high, we recommend regular screening in clinical practice.

SURGICAL CORRECTION OF POST-TRAUMATIC KYPHOSIS WITH OSTEOTOMIES IN THE SPINE

ABSTRACT Objective: To analyze the clinical and radiological evolution, indications and complications of the types of osteotomies in patients with disturbed sagittal balance (SB) resulting from post-traumatic kyphosis. The SB can be measured with a plumb line from the center of the body of C7 to S1, which allows recognizing the misalignment. The imbalance can be corrected by osteotomy. Methods: Thirty patients with SB loss due to post-traumatic kyphosis were studied from January 2014 to December 2017. SPO, PSO and VCR were performed to evaluate the degree of kyphosis before and after surgery, the Oswestry questionnaire was applied and the degree of correction, the days of hospital stay and transoperative bleeding were assessed. Results: Age, 50 years, SD = 14, follow-up time: 2-3 years. We performed 11 (36.7%) osteotomies of S-P, 17 (56.7%) pedicle subtractions and 2 (6.6%) vertebrectomies. Most of the lesions were found between levels L1 and L2; the complications were dehiscence of the surgical wound in 4 patients (13.3%) and infection in 2 (6.6%). The minimum surgical time was 3 hours; the Oswestry questionnaire did not showed statistically significant difference during the preoperative period, however, considerable improvement was observed 2 years after surgery. Conclusions: The use of corrective vertebral osteotomies significantly re-establishes the spinopelvic balance altered by different pathologies. It allows correcting in a single surgery the sagittal balance, achieving corrections from 10° to 40°, depending on the type of osteotomy performed, being a safe and effective procedure, which allows to restore the spinopelvic balance, improving the quality of life of the patients. Level of Evidence IIb; Prospective cohort study.

The risk factors of rod fracture after correction surgery with satellite rod in severe spinal deformity

Objective To investigate the incidence and risk factors for rod fracture after correction surgery with satellite rod in severe spinal deformity. Methods A retrospective analysis was made including 234 cases who underwent correction surgery using satellite rod technique for severe spinal deformity in our hospital from July 2012 to June 2017. At the last follow-up, a total of 6 patients were found to have rod fracture. All the patients had complete clinical and imaging data at the time of preoperation, postoperation, rod fracture occurring, post-revision and the last follow-up. The Cobb angle, the Global kyphosis (GK), the coronal balance (distance between C7 plumb line and center sacral vertical line, C7PL-CSVL) and the sagittal vertical axis (SVA) were measured respectively in the 6 patients with rod fracture during the follow-up process. The time, incidence and position of the broken rod were recorded, and the reasons of rod fracture were analyzed for each patient. Results The incidence of rod fracture was 2.6% (6/234) in the current study. The 6 patients included 3 males and 3 females with an average age of 34.5±15.4 years at initial surgery. The mean time of rod fracture was 24.0±17.7 months, of which 3 cases (50%) occurred within 1 years after operation. A total of 7 rods were broken, including 4 (57%) rods located at the single-rod-fixed side with stress concentration and 3 (50%) rods at the adjacent segment of the satellite rod. The average loss of correction was 20.8°±29.4° for Cobb angle and 34.0°±21.4° for GK. The potential reasons for rod fracture were listed as follows: 3 cases for residual kyphosis; 2 cases for pseudarthrosis; 3 cases for long fusion construct crossing lumbosacral junction; 1 case for trauma. Of the 6 patients with rod fracture, 3 (43%) patients underwent revision surgery by replacing the broken rods, adding satellite rod at the opposite side of pre-existing satellite rod and bone graft at the rod-breakage area. The other 3 patients underwent observation and no deterioration was found during follow-up. Conclusion The incidence of rod fracture after correction for severe spinal deformity with satellite rod is 2.6%. The broken rods are mainly located at the single-rod-fixed side with stress concentration or the adjacent segment of the satellite rod. Residual kyphosis, pseudarthrosis, long fusion construct crossing lumbosacral junction and trauma are the significant risk factors of rod fracture. Key words: Scoliosis; Kyphosi; Osteotomy; Internal fixators; Risk factors

Body posture and physical activity in children diagnosed with asthma and allergies symptoms: A report from randomized observational studies.

Asthma and body posture abnormalities in children and young people are major epidemiological problems worldwide. Asthma among children and adolescents, its relations with physical activity (PA) and PA relations with body posture were and are still being investigated.The aim of this study was to investigate how body posture is shaped in children diagnosed with asthma symptoms and whether body posture is associated with PA. The study involved 192 children. The main group consisted of 90 children diagnosed with asthma and allergies symptoms age 9 to 12 years old (x = 10.75 ± 1.08). The control group included 102 healthy children at the similar age (x = 10.64 ± 1.1). The level of activity has been assessed on the basis of a questionnaire and body posture assessments were done using a plumb line, pediscoliometer, digital inclinometer.Comparison of percentage of respondents fitting into body posture norms clearly indicates higher value in the group classified as active. In the group of participants diagnosed with asthma, percentage differences of participants with good body posture (without postural defects) were statistically significant. Among healthy children, percentages of the participants were higher in active children than in inactive children.Body posture is directly related to PA and the lack of activity affects disturbances within posturometric parameters. Prevention of body posture abnormalities is worth promoting in groups of children, also with various diseases including asthma and allergies symptoms.

Minimization of the Settling Time of Variable Area Flowmeters.

In the article a differential equation describing transient behavior of variable area (VA) meters has been developed and validated experimentally for air as a measured fluid and for two float shapes—plumb bob and sphere. A modified version of simplex algorithm adapted for nonlinear constraint optimization problems was applied to minimize the settling time of VA meters in two cases. In the first case both the float and tube geometry were altered. In the second case only the float geometry was modified. The second case has been validated experimentally. The theory and experiment is in reasonable agreement (under 5% of full scale), which is satisfactory for the purposes of optimization of VA flowmeters dynamic performance. Analytical model of VA flowmeter has been proven to be a proper tool for optimization. Settling times obtained during the optimization process were several times shorter than these of commercially manufactured instruments. Overshoot has not exceeded the assumed value of 3%.

Postoperative Lumbar Curve Progression Deteriorates Shoulder Imbalance in Patients with Lenke Type 2B/C Adolescent Idiopathic Scoliosis Who Underwent Selective Thoracic Fusion

To evaluate the association between postoperative lumbar curve progression and the shoulder height in patients with Lenke type 2B/C adolescent idiopathic scoliosis (AIS). A total of 25 patients with Lenke type 2B/C AIS underwent posterior correction surgery in our institution from 2005-2014 were included. Standing x-ray films of the whole spine obtained before surgery, immediately after surgery, and at the last follow-up were analyzed with respect to the following parameters: proximal thoracic Cobb angle, main thoracic (MT) Cobb angle, lumbar Cobb angle, lumbar apical vertebral translation, distance between C7 plumb line and the central sacral vertical line, and radiographic shoulder height (RSH). Correlations between the change of RSH and the changes of other parameters were analyzed both immediately after surgery and at the last follow-up. The change of RSH was significantly negatively correlated with both the change of MT Cobb angle (P< 0.05) and that of lumbar Cobb angle (P < 0.05) immediately after surgery, whereas the interval-time change of RSH was significantly positively correlated with the interval-time change of lumbar Cobb angle (P < 0.05) and that of lumbar apical vertebral translation (P < 0.05) at the last follow-up. The change of MT Cobb angle was an independent predictor for the change of RSH immediately after surgery, whereas the interval-time change of lumbar Cobb angle was an independent predictor for the interval-time change of RSH at the last follow-up. Postoperative lumbar curve progression is a risk factor for deterioration of shoulder imbalance in patients with Lenke 2B/C AIS during the follow-up period.

Coronal Imbalance After Three-Column Osteotomy in Thoracolumbar Congenital Kyphoscoliosis: Incidence and Risk Factors.

Retrospective radiographical clinical study. To investigate the incidence and risk factors of coronal imbalance (CI) after three-column osteotomy (3-CO) in patients with thoracolumbar congenital kyphoscoliosis (CKS). The incidence and risk factors of postoperative CI have been reported in adolescent idiopathic and degenerative lumbar scoliosis. However, limited data exists for patients with CKS after 3-CO. We reviewed a consecutive series of patients with CKS who underwent posterior-only 3-CO. Coronal curve patterns were classified according to absolute C7 translation values into: Type A, C7 translation is less than 30 mm; Type B, C7 translation more than or equal to 30 mm and C7 plumb line (C7PL) shifted to the concave side of the main curve; and Type C, C7 translation more than or equal to 30 mm and C7PL shifted to the convex side. CI was defined as C7 translation on either side more than or equal to 30 mm. According to C7 translation at the latest follow-up, patients was subdivided into an imbalanced group and a balanced group. One-hundred-thirty patients (mean age, 17.7 ± 5.2 yr) were recruited. The mean follow-up was 41.3 ± 18.5 months. Twenty-six patients (20%) were identified as having CI at the latest follow-up. Compared with the balanced group, the imbalanced group had a larger proportion of preoperative Type C pattern, higher main curve correction, and greater lowest instrumented vertebra (LIV) tilt before and after surgery. Multiple logistic regression showed that risk factors for CI were preoperative type C pattern, preoperative LIV tilt more than or equal to 23.5° and immediate postoperative LIV tilt more than or equal to 12.3°. The incidence of CI in patients with CKS after 3-CO was 20%. A preoperative type C pattern, preoperative LIV tilt more than or equal to 23.5°, and immediate postoperative LIV tilt more than or equal to 12.3° were found to be associated with CI at the latest follow-up. 3.

The relationship between global spinal alignment and pelvic orientation from standing to sitting following pedicle subtraction osteotomy in ankylosing spondylitis patients with thoracolumbar kyphosis.

To investigate the relationship between the spinal sagittal alignment and arc of pelvic motion from standing to sitting in ankylosing spondylitis (AS) patients with thoracolumbar kyphosis following pedicle subtraction osteotomy (PSO). AS patients who underwent PSO for thoracolumbar kyphosis from January 2016 to July 2018 were recruited. EOS standing and sitting images were obtained pre- and postoperatively. Radiographic parameters were measured on the sagittal radiographs, including lumbar lordosis, thoracic kyphosis, pelvic incidence, pelvic tilt, sacral slope, sagittal vertical axis (SVA), spinosacral angle, anterior pelvic plane angle (APPA) and knee flexion angle. Thirty-six patients were enrolled. From standing to sitting, APPA was increased by a mean of 14.7° (P < 0.001) and 3.0° (P = 0.083) before and after surgery, respectively. The increase in APPA from standing to sitting was correlated with the standing SVA (R = 0.592, P < 0.001) preoperatively. After PSO, the change in APPA was correlated with the change in SSA in both the standing and sitting position (R = 0.381, P = 0.022 and R = 0.667, P < 0.001, respectively). The APPA from standing to sitting was decreased in 11 patients with standing C7 plumb line posterior to the femoral head postoperatively. In AS patients, pelvic orientation was adjusted by the global spinal alignment. When planning total hip arthroplasty for AS patients, global spinal alignment should be considered to improve the joint stability.

Rational placement of measuring systems in high dams

To solve the problem of rational placement of measuring systems in concrete dams, the experience of full-scale observations of horizontal displacements and stresses in the body of the arch dam of Inguri HPP (Georgia) was used with the use of statistical processing of the results of observations and the Barlow-Hunter-Proshan mathematical model. The type of the law of distribution of horizontal displacements and arch stresses was established by analyzing the histograms of these measured indicators of the static state of the structure. It is established that the change of horizontal displacements along the dam height is well described by the one-sided normal distribution law, and the arch stresses in the controlled alignment - by the normal distribution law. The laws of distribution of random variables are established. Using the Barlow-Hunter-Proshan mathematical model enabled the use of economic criteria on the basis of the frequency characteristics of the indicators of trouble-free operation of the construction and obtain the recurrence relation for the sequence of coordinate points of the measuring systems. The results of calculations of the coordinates of the recommended location of straight plumb lines in the center console and tensometric rosettes in the measuring range of the Ingur dam at the level of 210 m for a rational placement scheme are presented. The calculation showed that the number of measuring systems installed in the body of the Ingur dam exceeds the optimum value.

Exploring Brow Position Changes with Age in Koreans.

PurposeSeveral studies have described age-associated brow drooping in Westerners. However, there are few studies that address brow drooping in the Asian population, and especially in the Korean population. Therefore, we studied brow position changes with age in Korean individuals.MethodsA total of 300 adults older than 18 years were enrolled. The ImageJ program was used to analyze digital photos of the patients by measuring the following parameters: marginal reflex distance-1, brow-to-pupil distance, nasal ala-lateral brow distance, lateral brow plumb line, and the angle formed by the line from the mid pupil to the midline of the brow and a line from the midline of the brow to the lateral brow. We divided the patients into three groups (18 to 40, 41 to 60, older than 61) and compared them using the ANOVA test.ResultsGroup A included 100 patients between 18 and 40 years of age. Group B included 100 patients between 41 and 60 years of age. Group C included 100 patients older than 61 years. There were significant differences between groups A and C and between groups B and C with regard to marginal reflex distance-1, brow-to-pupil distance and the angle. Lateral brow plumb line showed significant difference only between groups A and B. Nasal ala-lateral brow distance was not significantly different across the three groups.ConclusionsWe sought to describe the physiologic facial changes that occur in Korean individuals. We also hoped to establish guidelines for ptosis corrective surgery. We used various parameters to characterize the aging process in Asians. Our data demonstrated that, like Westerners, Koreans experience lateral brow drooping with age; however, this change was only significant in the group aged >61 years.